262 research outputs found
Strangers Along the Trail: Peoria’s Shaker Apostates Enter the World
In the 1830s, Peoria, Illinois, became the home of a remarkable group of immigrants whose origins were unknown to their contemporaries and overlooked by historians for nearly 150 years. They were Shaker apostates, political and religious refugees from the utopian settlement of Pleasant Hill, Kentucky, a Shaker community noted for members’ communal ownership of property, dedication to altruistic labor, and the Shaker faith that demanded strict celibacy. The apostates’ lives cover two periods: first, at Pleasant Hill, where their dedication to an ideal of religious and social perfection demanded that they abandon worldly ties and family bonds; and second, in “the World,” which called for just the opposite. Their struggles and success in both realms are remarkable and testify both to the force and success of altruistic communal initiatives and centralized power as well as the countervailing force of bonds of marriage and family, democratic decision making, and private ownership of property
Proton Therapy for Uveal Melanoma in 43 Juvenile Patients: Long-Term Results.
PURPOSE: To examine the metastatic and survival rates, eye retention probability, and the visual outcomes of juvenile patients after proton beam radiotherapy (PBRT) for uveal melanoma (UM).
DESIGN: Retrospective case-factor matched control study.
PARTICIPANTS AND CONTROLS: Forty-three patients younger than 21 years treated with PBRT for UM were compared with 129 matched adult control patients.
METHODS: Information on patient demographics and clinical characteristics were recorded before and after treatment from patients' files. The control group was composed of adult patients (>21 years) matched for tumor size (largest tumor diameter, ±2 mm; height, ±2 mm) and anterior margin location (iris, ciliary body, pre-equatorial or postequatorial choroid). For each juvenile patient, 3 adults were selected.
MAIN OUTCOME MEASURES: Comparing outcomes of juvenile and adult patients in terms of metastatic and eye retention rates using the log-rank statistic, relative survival using the Hakulinen method, as well as their visual outcomes.
RESULTS: Forty-three juvenile and 129 control cases were reviewed. The metastatic rate at 10 years was significantly lower in juvenile UM patients than in adult controls (11% vs. 34%; P <0.01), with an associated relative survival rate of 93% versus 65% (P = 0.02). Six juvenile patients (14%) demonstrated metastases. One patient underwent enucleation because of a presumed local tumor recurrence and 4 additional patients underwent enucleation because of complications (9.3%). In the adult control group, 27% (n = 35) of matched patients demonstrated metastases, there were 2 cases of local recurrence, and 16% (n = 21) underwent enucleation because of complications. A visual acuity of more than 0.10 was maintained in most cases, without any significant differences before or after treatment observed between both groups.
CONCLUSIONS: After PBRT, metastatic and survival rates are significantly better for juvenile than for adult patients with UM. Clinically, juvenile and adult eyes react similarly to PBRT, with patients having a comparable eye retention probability and maintaining a useful level of vision in most cases. This is the largest case-control study of proton therapy in juvenile eyes to date and further validates PBRT as an appropriate conservative treatment for UM in patients younger than 21 years
Inverse plan optimization accounting for random geometric uncertainties with a multiple instance geometry approximation (MIGA)
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135142/1/mp1016.pd
Dosimetric characterization of a microDiamond detector in clinical scanned carbon ion beams
Purpose: To investigate for the first time the dosimetric properties of a new commercial synthetic diamond detector (PTW microDiamond) in high-energy scanned clinical carbon ion beams generated by a synchrotron at the CNAO facility. Methods: The detector response was evaluated in a water phantom with actively scanned carbon ion beams ranging from 115 to 380 MeV/u (30-250 mm Bragg peak depth in water). Homogeneous square fields of 3×3 and 6×6 cm2 were used. Short- and medium-term (2 months) detector response stability, dependence on beam energy as well as ion type (carbon ions and protons), linearity with dose, and directional and dose-rate dependence were investigated. The depth dose curve of a 280 MeV/u carbon ion beam, scanned over a 3×3 cm<sup>2</sup> area, was measured with the microDiamond detector and compared to that measured using a PTW Advanced Markus ionization chamber, and also simulated using FLUKA Monte Carlo code. The detector response in two spread-out-Bragg-peaks (SOBPs), respectively, centered at 9 and 21 cm depths in water and calculated using the treatment planning system (TPS) used at CNAO, was measured. Results: A negligible drift of detector sensitivity within the experimental session was seen, indicating that no detector preirradiation was needed. Short-term response reproducibility around 1% (1 standard deviation) was found. Only 2% maximum variation of microDiamond sensitivity was observed among all the evaluated proton and carbon ion beam energies. The detector response showed a good linear behavior. Detector sensitivity was found to be dose-rate independent, with a variation below 1.3% in the evaluated dose-rate range. A very good agreement between measured and simulated Bragg curves with both microDiamond and Advanced Markus chamber was found, showing a negligible LET dependence of the tested detector. A depth dose curve was also measured by positioning the microDiamond with its main axis oriented orthogonally to the beam direction. A strong distortion in Bragg peak measurement was observed, confirming manufacturer recommendation on avoiding such configuration. Very good results were obtained for SOBP measurements, with a difference below 1% between measured and TPS-calculated doses. The stability of detector sensitivity in the observation period was within the experimental uncertainty. Conclusions: Dosimetric characterization of a PTW microDiamond detector in high-energy scanned carbon ion beams was performed. The results of the present study showed that this detector is suitable for dosimetry of clinical carbon ion beams, with a negligible LET and dose-rate dependence
Clinical practice guidelines of the European Association for Endoscopic Surgery (EAES) on bariatric surgery: update 2020 endorsed by IFSO-EC, EASO and ESPCOP
Background:
Surgery for obesity and metabolic diseases has been evolved in the light of new scientific evidence, long-term outcomes and accumulated experience. EAES has sponsored an update of previous guidelines on bariatric surgery.
Methods:
A multidisciplinary group of bariatric surgeons, obesity physicians, nutritional experts, psychologists, anesthetists and a patient representative comprised the guideline development panel. Development and reporting conformed to GRADE guidelines and AGREE II standards.
Results:
Systematic review of databases, record selection, data extraction and synthesis, evidence appraisal and evidence-to-decision frameworks were developed for 42 key questions in the domains Indication; Preoperative work-up; Perioperative management; Non-bypass, bypass and one-anastomosis procedures; Revisional surgery; Postoperative care; and Investigational procedures. A total of 36 recommendations and position statements were formed through a modified Delphi procedure.
Conclusion:
This document summarizes the latest evidence on bariatric surgery through state-of-the art guideline development, aiming to facilitate evidence-based clinical decisions
Religious affiliation modulates weekly cycles of cropland burning in Sub-Saharan Africa
Research ArticleVegetation burning is a common land management practice in Africa, where fire is used
for hunting, livestock husbandry, pest control, food gathering, cropland fertilization, and
wildfire prevention. Given such strong anthropogenic control of fire, we tested the hypotheses
that fire activity displays weekly cycles, and that the week day with the fewest fires
depends on regionally predominant religious affiliation.We also analyzed the effect of land
use (anthrome) on weekly fire cycle significance. Fire density (fire counts.km-2) observed
per week day in each region was modeled using a negative binomial regression model, with
fire counts as response variable, region area as offset and a structured random effect to
account for spatial dependence. Anthrome (settled, cropland, natural, rangeland), religion
(Christian, Muslim, mixed) week day, and their 2-way and 3-way interactions were used as
independent variables. Models were also built separately for each anthrome, relating
regional fire density with week day and religious affiliation. Analysis revealed a significant
interaction between religion and week day, i.e. regions with different religious affiliation
(Christian, Muslim) display distinct weekly cycles of burning. However, the religion vs. week
day interaction only is significant for croplands, i.e. fire activity in African croplands is significantly
lower on Sunday in Christian regions and on Friday in Muslim regions. Magnitude of
fire activity does not differ significantly among week days in rangelands and in natural
areas, where fire use is under less strict control than in croplands. These findings can contribute
towards improved specification of ignition patterns in regional/global vegetation fire
models, and may lead to more accurate meteorological and chemical weather forecastinginfo:eu-repo/semantics/publishedVersio
High workload and job stress are associated with lower practice performance in general practice: an observational study in 239 general practices in the Netherlands
Contains fulltext :
80493.pdf (publisher's version ) (Open Access)BACKGROUND: The impact of high physician workload and job stress on quality and outcomes of healthcare delivery is not clear. Our study explored whether high workload and job stress were associated with lower performance in general practices in the Netherlands. METHODS: Secondary analysis of data from 239 general practices, collected in practice visits between 2003 to 2006 in the Netherlands using a comprehensive set of measures of practice management. Data were collected by a practice visitor, a trained non-physician observer using patients questionnaires, doctors and staff. For this study we selected five measures of practice performance as outcomes and six measures of GP workload and job stress as predictors. A total of 79 indicators were used out of the 303 available indicators. Random coefficient regression models were applied to examine associations. RESULTS AND DISCUSSION: Workload and job stress are associated with practice performance.Workload: Working more hours as a GP was associated with more positive patient experiences of accessibility and availability (b = 0.16). After list size adjustment, practices with more GP-time per patient scored higher on GP care (b = 0.45). When GPs provided more than 20 hours per week per 1000 patients, patients scored over 80% on the Europep questionnaire for quality of GP care.Job stress: High GP job stress was associated with lower accessibility and availability (b = 0.21) and insufficient practice management (b = 0.25). Higher GP commitment and more satisfaction with the job was associated with more prevention and disease management (b = 0.35). CONCLUSION: Providing more time in the practice, and more time per patient and experiencing less job stress are all associated with perceptions by patients of better care and better practice performance. Workload and job stress should be assessed by using list size adjusted data in order to realise better quality of care. Organisational development using this kind of data feedback could benefit both patients and GP
A three-year cohort study of the relationships between coping, job stress and burnout after a counselling intervention for help-seeking physicians
<p>Abstract</p> <p>Background</p> <p>Knowledge about important factors in reduction of burnout is needed, but there is a dearth of burnout intervention program studies and their effects among physicians. The present three-year follow-up study aimed to investigate the roles of coping strategies, job stress and personality traits in burnout reduction after a counselling intervention for distressed physicians.</p> <p>Methods</p> <p>227 physicians who attended a counselling intervention for burnout at the Resource Centre Villa Sana, Norway in 2003-2005, were followed with self-report assessments at baseline, one-year, and three-year follow-up. Main outcome measures were emotional exhaustion (one dimension of burnout), job stress, coping strategies and neuroticism. Changes in these measures were analyzed with repeated measures ANOVA. Temporal relationships between changes were examined using structural modelling with cross-lagged and synchronous panel models.</p> <p>Results</p> <p>184 physicians (81%, 83 men, 101 women) completed the three-year follow-up assessment. Significantly reduced levels of emotional exhaustion, job stress, and emotion-focused coping strategies from baseline to one year after the intervention, were maintained at three-year follow-up.</p> <p>Panel modelling indicated that changes in emotion-focused coping (z = 4.05, p < 0.001) and job stress (z = 3.16, p < 0.01) preceded changes in emotional exhaustion from baseline to three-year follow-up. A similar pattern was found from baseline to one-year follow-up.</p> <p>Conclusion</p> <p>A sequential relationship indicated that reduction in emotion-focused coping and in job stress preceded reduction in emotional exhaustion. As a consequence, coping strategies and job stress could be important foci in intervention programs that aim to reduce or prevent burnout in help-seeking physicians.</p
A GPU implementation of a track-repeating algorithm for proton radiotherapy dose calculations
An essential component in proton radiotherapy is the algorithm to calculate
the radiation dose to be delivered to the patient. The most common dose
algorithms are fast but they are approximate analytical approaches. However
their level of accuracy is not always satisfactory, especially for
heterogeneous anatomic areas, like the thorax. Monte Carlo techniques provide
superior accuracy, however, they often require large computation resources,
which render them impractical for routine clinical use. Track-repeating
algorithms, for example the Fast Dose Calculator, have shown promise for
achieving the accuracy of Monte Carlo simulations for proton radiotherapy dose
calculations in a fraction of the computation time. We report on the
implementation of the Fast Dose Calculator for proton radiotherapy on a card
equipped with graphics processor units (GPU) rather than a central processing
unit architecture. This implementation reproduces the full Monte Carlo and
CPU-based track-repeating dose calculations within 2%, while achieving a
statistical uncertainty of 2% in less than one minute utilizing one single GPU
card, which should allow real-time accurate dose calculations
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